1. Field of the Invention
The present invention relates to a novel water-absorptive material and a method of producing a water-absorptive molded product.
2. Discussion of Background
Heretofore, a highly water-absorptive polymer has been widely used for sanitary goods such as a diaper and a sanitary towel, agricultural and gardening goods such as a water-holding agent, and other various uses which require water-absorptivity, and its utility is generally appreciated. Generally known examples of the water-absorptive polymer include polyacrylate type, starch type or cellulose type polymers in various forms of powder or fiber.
These known polymers exhibit a satisfactory water-absorptivity to ion-exchanged water (deionized water), but do not exhibit a satisfactory water-absorptivity to an ionic aqueous solution. However, most of these water-absorptive polymers are used in connection with an ionic aqueous solution, and it is therefore strongly demanded in this technical field to improve the water-absorptivity of these polymers in the ionic aqueous solution.
These water-absorptive polymers alone can not be molded into a sheet or the like, and they are used in a form of powder. Thus, it is necessary to disperse and maintain the powdery polymer in a fibrous substrate such as a paper or a non-woven cloth, and it is therefore inconvenient to prepare a final product. Also, the final product thus prepared sometimes do not have a high water-absorptivity. Moreover, these conventionally known water-absorptive polymers are usually poor in fabricability, and it is therefore hard to be stretched or made into a composite.
There are some water-absorptive polymers which can be molded into products by themselves, but their types are limited. Thus, there are few water-absorptive polymers which satisfy both fabricability and high water-absorptivity.